Blackjack Strategy: Doubling Down

While most new blackjack players can quickly grasp the ideas of when to hit or stand, the decision between simply hitting and doubling down can trip up even more experienced players. Doubling down is one of the most powerful tools a player has to even up their odds against the casino, so knowing the appropriate times to double down (and when not to) is critical to any basic blackjack strategy.

In most forms of blackjack games, players are allowed to double down with any two card starting hand, and cannot double down once they have three or more cards. To double down, a player places a second bet of equal or lesser value to their original bet, for which they receive just one more card – after which they must stand.

When to Double Down – Hard Hands

Hard hands – those without an ace that still counts as 11 points – are much simpler to play in general, and this extends to double down play. Here’s a handy and easy-to-memorize guide for when to double down with a hard hand:

  • Hands of 8 or less: Never double down with these hands. Sure, it’s very tempting to double down with an 8 against a dealer showing a 5 or 6, but you’ll do a little better by simply hitting even in those spots.
  • Hands of 9: Here, doubling down starts to become a profitable play against the world dealer hands. If they dealer is showing a card in the range of 3-6, doubling down is the right move.
  • Hands of 10: Now you’ll be doubling down a whole lot against most dealer cards. If the dealer is showing 9 or less, it’s time to double down.
  • Hands of 11: This is the best starting hand for doubling down. Here, you’ll double down against a dealer that’s showing anything other than an ace.
  • Hands of 12 or more: Don’t even think about it – doubling down is never the right move with a hard hand of 12 or more.

When to Double Down in Blackjack – Soft Hands

Soft hands are a bit trickier to figure out for most players, and the proper times to double down with them require a little more work to memorize. There are even some minor changes on what you should do depending on what the rules in your game say the dealer must do with a soft 17. Here’s a quick guide:

  • Soft hands of 13 or 14: Double down only against a dealer 5 or 6; otherwise, simply hitting is the best play.
  • Soft hands of 15 or 16: Double down against a dealer 4-6; against other hands, just hit.
  • Soft hands of 17: Double down against a dealer showing anything in the range of 3-6; otherwise, hitting is the thing to do.
  • Soft hands of 18: Here’s where it gets tricky! If you’re playing in a game where the dealer stands on a soft 17, you should double down if the dealer is showing 3-6, hit if the dealer is showing a 9 or higher, and stand against other hands. Against a dealer who must hit on soft 17, you should essentially do the same – except that you should also double against a 2, rather than standing.
  • Soft hands of 19 or more: Always stand with these hands, with one exception; against a dealer who hits of soft 17, hit if the dealer is showing a 6.

Why We Double Down in Blackjack

Doubling down naturally puts the player at something of a disadvantage, since you give up the option of making further hits later in the hand. So why do we want to put more money on the line while lowering the odds that we’ll actually win the hand?

Obviously, with most hands, this is a bad deal. However, when the player has a huge advantage against the house, lowering that advantage just slightly can be well worth it if we get to wager twice as much money, since that means our overall edge actually goes up. For example, if you make a $10 bet and have a 9 against a dealer 6, you can expect to make about $1.96 on average when you choose to hit. By doubling down, you can only expect to make about $1.58 on that first $10 – but you’ll also make the same amount on the second $10 you put down, pushing your total profits up to $3.17.